Air gauge



July 19 1927' F. G. JOHNSON AIR GAUGE Filed Aug. 5. 1925 l Il,

Patented July 19, 1927.

UNITED STATES PATENT OFFICE.

FREDERICK GODFREY JOHN SON, OI' NEW HAVEN, CONNECTICUT, .ASSIGNOR TO VISIBLE TIRE GAUGE CO., F NEW HAVEN, CONNECTICUT, A CORPORATION.

AIB GAUGE.

Application tiled August 5, 1.925. Serial No. 48,190.

F ig. 1 is a face View of an Vair gauge con structed in accordance with my invention.

Fig. 2 is a vertical, sectional view of the same, on an enlarged scale.

Fig. 3 is a face view, with the dial removed.

Fig. 4 is a plan viewof the rack, detached. This invention relates to an improvement in air gauges, and While particularly adapt' ed for air gauges to be applied to the fillingnipples of automobile tires, is readily adaptable for various other purposes.'I In assembling tire gauges, provision must be made for adjustments, so the pointer will properlyI register with the dial at'predetermined pressures, and one object of this invention is to provide means for readily makin this adjustment. In some forms of W eels, the gauge projects so far toward the hub that access cannot be had for attachment to the pump, and another object of this invention is to provide a tire gauge with a forwardlyprojecting stem to which a tire-pump-ooupling may be conveniently attached, and the' invention consists in the construction as hereinafter described and particularlyrecited inthe claim.

' In car r in out m invention, I form the gauge wit a ase 5 or attachment to a tireni ple, or other device. Above the base is a ousing 6 and projecting forward from the up er end of the housing is a stem 7. Exten ing from the base upward through therear wall 8 of the housing and outward 36 through the stem 7, isan air-passage 9. In the stem 7 is the usual valve, not shown, but having a pin 10C ro'ectin beyond the end of the stem 7, w ic is t readed for couling with a pump, the valve being o ened y inward pressure Aupon the pin '10. n the housin -is a Bourdon tube 11, one end of which is fixed in the housing, over a port 12 opening out of the base 5. The closed end of the tube is soldered to a wire 13, the outer end 14 of this wire being turned inward through a radial slot 15 formed in a disk 16 mounted on a stud 17. This disk is formed with a segmental rack 18 which gneshes with a pinion 19 fixed to a central arbor 20, which carries a pointer 21. -In one direction, the central arbor 2O turns against the pressure of a spring 22, one end of which is fixed to the arbor, and the other end to a stud 23, the pinion 19 and disk 16 being held in place upon a. plate 24. The movement of the pointer 21 is limited in one direction by a pin 25 mounted in a dial 26, which may be suitably raduated.

In or er that the pointer may properly register on the dial, according to the amount of pressure, the connection between the end of the Bourdon tube and the disk 16 must be adjustable and by using a wire this connection can be curved or` crim ed, so as to shorten it, and by providing t e slot 15, the end of this wire may be moved toward or away from the center of the rack-disk, so that the movement of the Bourdon tube, under pressure will be properly indicated on the dial, it ein understood that as air is forced into the tire-tube, or other device, air will pass through the port 12 into the Bourdon tube 11, and tend to straighten it, and this movement is im arted to the rack through the wire-connection 13. The 'stem 7, projecting forward, is in convenient osition for connection with the pump-tu and by carefully adjusting the coupling-wire 13, the movement of the pointer can be adjusted so as to properly indicate the pressure on the dial.

While air gauges using a Bourdon tube adapted to actuate a pointer to indicate airpressure are not new, my particular arrangement simplifies the construction by the omission of and sim licit of parts, which leads to lower cost o pro uction and permits of more perfect adjustment of parts, and also leads to a more I claim: An air auge, comprising a housing, a

perfect operation.

Bourdon tu mounted in the housing, a center arbor, a pinion mounted thereon, a rack meshing with said pinion, said rack rovided with an integral central disk' forme with a radial slot, and a Wire soldered directly to and forming a rigid operativmextension of the closed end lof the Bourdon tube, and its outer .ei'id'turned into said slot..

In testimony whereof, I havelsigned this ecification. v

REDERICK GODFREY JOHNSON. 

